The subject invention refers to a two-stroke internal combustion engine comprising a cylinder with a movable piston in it, which cylinder at its one end has a combustion chamber and at its other end is connected to a crankcase, whereby the crankcase and the combustion chamber are mutually connected via a scavenging duct, whose opening and closing is controlled by the movement of the piston, and a carburetor is via an inlet port connected to the crankcase.
In a conventional two-stroke internal combustion engine an air/fuel mixture is led from the carburetor to the crankcase and from there via one or several scavenging ducts to the combustion chamber. The path from the carburetor to the combustion chamber will thereby become relatively long. Furthermore, the crankcase has a volume, which is approximately five times as large as the cylinder volume. Besides that, in order to reach the combustion chamber the fuel must be vaporized. When starting the engine this means, particularly when the engine is cold, that the engine""s crankcase must rotate a lot before a combustible air/fuel mixture will reach the combustion chamber. Starting the engine thus requires more time and effort than what would be desirable. This is a disadvantage, particularly when the engine has a manually operated starter device, such as a cord starter device, but also when the engine is equipped with a starter.
The purpose of the subject invention is to eliminate or at least reduce the above-mentioned disadvantage and to achieve a two-stroke engine having an essentially improved startability. This is achieved in an internal combustion engine of the kind mentioned initially, and which in accordance with the invention is mainly characterized in that it comprises a device for supply of fuel to the scavenging duct adjacent to the combustion chamber in order to simplify starting of the engine.